1. Field of the Invention
The present invention relates to an electrostatic discharge (ESD) protection semiconductor structure. More particularly, the present invention relates to a ESD protection semiconductor structure with adjustable multi-trigger or single-trigger voltage, which has improved ESD protection capability and can meet different power standards by adjusting the discharge capacities of a plurality of N-wells or P-wells in P-substrate and connecting the N-wells or P-wells in parallel, and which demonstrates better performance than the performance of the conventional ESD protection semiconductor structure.
2. Description of Related Art
ESD protection circuits are used especially for ESD protection in ICs. When the power in the ESD protection circuits keeps increasing and the ESD protection device reaches the secondary breakdown voltage after reaching the first breakdown voltage, the ESD protection device or the ESD protection function thereof may be damaged due to the high voltage or current.
The secondary breakdown voltage is usually dominated by the breakdown voltage of the PN interface of a bipolar junction transistor (BJT) is used as the ESD protection device, that means, after the first breakdown, if the power in the ESD protection circuit keeps increasing, the increases of voltage and current through the device will trigger the secondary breakdown voltage first, which causes damage to the device.
Accordingly, a semiconductor structure serving as the ESD protection device to prevent from reaching secondary breakdown can meet the requirement of practical application.